The present invention relates to catheters for selective placement in a right or left coronary artery of a patient by transradial approach.
In diagnosing and treating heart diseases caused by occlusion of the coronary arteries, a physician may perform various tests and non-surgical procedures in which a catheter is guided through an artery in the arm or leg and into the selected coronary artery of the heart. Once in place, the catheter is then used for performing diagnostic tests such as a coronary angiography in which a radioimaging material is injected to visualize the arteries, or therapeutic interventions such as a coronary angioplasty, stenting, or atherectomy.
In a femoral catheterization procedure, the catheter is introduced into the aorta via the femoral artery in the leg. A drawback of this procedure is that, after it is completed, the patient must remain flat and immobilized with pressure applied to the wound for an extended period of time of about 4-6 hours to ensure that the bleeding stopped.
With a brachial catheterization, the catheter is introduced via the brachial artery in the arm. With this procedure, the patient can be up and walking within a shorter rest period of only about 1-2 hours. However, the deep location of the artery leads to increased bleeding complications, and thrombosis of the artery can occur. Another disadvantage is that a catheter inserted into the brachial artery undesirably cuts off blood flow into the lower arm, wrist and hand. In addition, the shapes of the distal end of coronary catheters that have been described for insertion using a brachial artery approach, such as those in U.S. Pat. Nos. 5,299,574 (Bower) and 5,471,986 (Ishimura), could be improved to more securely maintain the tip of the catheter engaged within the artery and prevent it from backing out of the coronary ostium when angioplasty equipment is advanced into the artery.
A relatively new technique is a transradial approach in which the catheter is introduced into the aorta via the radial artery in the wrist. The radial artery and the ulnar artery are two small arteries in the wrist that communicate through the palmar arch. Advantageously, insertion of a catheter into the radial artery does not cut off blood flow into the lower arm or hand because the blood can continue to flow through the ulnar artery and palmar arch. This approach also requires a relatively short recovery time of about 10-15 minutes to ensure that bleeding has stopped from the surgical wound. Thus, an advantage of the use of a transradial approach for diagnostic catheterization and intervention over femoral or brachial coronary intervention approaches is the early discharge of the patient into outpatient care, and the cost reductions associated with the early discharge and increased availability of recovery beds. In addition, transradial intervention procedures can be performed in a less complicated setting than is required in a femoral or brachial procedure. However, since this approach for coronary angiography was first described in 1989 by Dr. Lucien Campeau (Cathet. Cardiovasc. Diagn. 16:3-7 (1989)), it has gained acceptance in Europe, but only minimal acceptance in the United States. A barrier to the use of this technique is that existing catheters are not designed for optimal use from the radial artery. Current catheters require excessive manipulation and become easily dislodged during examination or treatment.
Therefore, an object of the invention is to provide a catheter for use in coronary diagnosis and/or treatment that is specifically configured for insertion into a coronary artery via a transradial approach. Another object is to provide a right and left radial catheter having a shape such that, when a force is applied that tends to displace the catheter tip out of the ostium of the artery, such as when advancing equipment and/or injecting a dye through the catheter into the artery, the tip of the catheter will not become dislodged and will remain securely seated in the ostium of the artery until completion of the procedure. Yet another object is to provide catheters that require minimal manipulation to engage the coronary ostium, thereby facilitating the ease of the procedure.
These and other objects and advantages are achieved in right and left coronary catheters that are designed to be used from the right arm with arterial entry from the radial artery. Also provided are methods of inserting the catheters into a right or left coronary artery of a patient using a transradial approach, and the use of the catheters in coronary catheterization procedure to selectively deliver a dye material, medical tool or other therapeutic device to the coronary artery of interest.
The radial catheters of the invention have a proximal end, a shaped distal end that is configured for placement in or near the right or left coronary artery, and an extended and relatively straight body portion therein between. The length of the catheter is sufficient to allow advancement of the distal end portion of the catheter into the aorta and the insertion of the tip into the ostium of the selected coronary artery using a transradial approach. The preformed distal end of the catheters includes two curved portions, or bends, that are sufficiently angled such that when the catheter is advanced into the aorta, the tip of the catheter can be engaged in the ostium of the selected coronary artery and maintained therein against counterforces that tend to displace the tip from the artery.
The distal end of the catheters includes a first curved portion, or segment, that defines a first angle and is disposed distally of the elongate body portion of the catheter, a second curved portion that defines a second angle, a straight portion that is disposed between the first and second curved portions, and a tip portion with a tip that is disposed distally of the second curved portion. The second curved portion of the right radial catheter is angled toward the first curved portion, giving the catheter a xe2x80x9cJxe2x80x9d-shaped appearance. The left radial catheter is xe2x80x9cUxe2x80x9d-shaped with the second curved portion of the distal end curved away from the first curved portion.
In use, the distal end of the radial catheters is inserted into the radial artery at the wrist or brachial artery in the arm, and advanced into the aorta via the innomirnate artery through the aortic arch and into the ascending aorta. The curvature of the distal end of the right radial catheter is such that when the first curved portion is placed against the medial wall of the ascending aorta, the straight portion and the tip portion are oriented toward the opposing lateral wall of the aorta and the right coronary artery, and the tip is placed in or near the coronary ostium. In the right radial catheter, it is preferred that the angle of the first curved portion is sufficient to position the elongate body portion and the straight portion of the distal end relative to each other at an about 40-60xc2x0 angle, and the second angle is sufficient to position the straight portion of the distal end relative to the tip portion at an about 80-110xc2x0 angle.
The left radial catheter of the invention is configured so that when the first curved portion is positioned against the medial wall of the ascending aorta, the second curved portion is directed toward and rests against the opposing lateral wall of the aorta so that the approach to the left coronary artery is from the contra-lateral wall, and the tip is placed in or near the coronary ostium. This configuration and contact of the curved portions of the distal end with the aortic wall provides resistance against forces that tend to flex the catheter tip out of the artery during use. Preferably, the first angle of the distal end portion of the left radial catheter is sufficient to position the elongate body portion of the catheter and the straight portion of the distal end at an about 20-40xc2x0 angle relative to each other, and the second angle is sufficient to position the straight portion and the tip portion of the distal end relative to each other at an about 135-155xc2x0 angle.
The present transradial coronary catheters provide a stable and reliable device for performing transradial coronary intervention procedures, and eliminate the need to conduct such procedures using a femoral or brachial catheterization approach. Advantageously, the shapes of the present radial catheters provide a catheter in which engagement of the tip with the selected coronary artery can be maintained against counterforces that tend to dislodge and cause the tip to back out of the artery, such as those that arise when advancing a tool through the catheter into the artery. The configuration of the distal end of the catheters, including the angles, or bends, of the curved portions, the placement and contact of one or both of the curved portions with the aortic wall, and the biasing force of the bends, cooperate to maintain the catheter tip within the coronary artery, and provide a secure and dependable instrument for conducting coronary diagnosis and treatment procedures. The stiffness of the material used to construct the catheter can also contribute to maintaining the catheter tip in the artery by varying the flexibility of the bends. The distal end of the radial catheters can also be easily positioned in the desired location within the aorta with minimal manual manipulation.